| abstract |
The film thickness is 10 μm, the weight retention when held at 400 ° C. for 4 hours is 99.0% or more, the YI (yellowness) is 10 or less, and the linear thermal expansion between 100 and 350 ° C. A polyimide film having a coefficient of 55 ppm / K or less is disclosed. This polyimide film is excellent in transparency and heat resistance and has a low coefficient of linear thermal expansion, and can be suitably used for a substrate for a display, a touch panel, or a solar cell, for example. |